Online Multiple-Aircraft Collision Avoidance Method

A new method for online multiple-aircraft collision avoidance using an autonomous dependent surveillance-broadcast system is proposed. The key objective is to take advantage of satellite-based navigation technology to improve some deficiencies in the existing traffic collision avoidance system (TCAS). First, a brief review of TCAS and airborne collision avoidance system development is presented. Pros and cons of the existing system and critical gaps for future air traffic management are discussed. Next, a new method and its associated algorithmic development are proposed for multiple-aircraft collision avoidance. The proposed method is based on a collision risk map formulation in future dense airspace. A priority indexing method is used to reduce the complexity of trajectory optimization for real-time decision support. Dijkstra's algorithm is used to find cost-minimized trajectories for each aircraft to avoid collision. Convergence behavior and computationally efficient features of the method are investigated in detail. Several demonstration examples are illustrated to show the benefits of this method. Finally, comparison with the existing method and several major conclusions are drawn, based on the proposed study.